Drymeia glacialis (Rondani, 1866)

Savage, Jade & Sorokina, Vera S., 2021, Review of the North American fauna of Drymeia Meigen (Diptera, Muscidae) and evaluation of DNA barcodes for species-level identification in the genus, ZooKeys 1024, pp. 31-89 : 31

Drymeia glacialis (Rondani, 1866) Figs 2H , 4E , 6E

Aspilia glacialis Rondani, 1866: 87.

Pogonomyia alpicola Rondani, 1871: 337. syn. nov.

Pogonomyia alpicola var. tundrica , Schnabl in Becker et al. 1915: 48.

Type material examined.

None.

Other material examined.

More than 100 males and females: Nearctic: USA: Colorado: Cameron Pass, Cottonwood Pass (Chaffee Co.), Echo Lake ( Mt. Evans ), Floral Park , Independance Pass ( Lake Co. ), Loveland Pass , Nederland , Summit Lake ( Mt. Evans ); Wyoming: Delaey Creek Park , Snowy Range Mts. , Togwotee Pass ( Teton Co. ). Palaearctic : Austria: Hohe Tauern Nat. Pk., Igls, Obergurgl ; Italy: Karthaus ; Mongolia: Ara-Khangaiskii aimak, 7 km SW Taryata ; Russia: Altai Republic, Khakasiya, Tyva; Switzerland: Julierpass ( BUIC, CNC, SZMN) .

Distribution.

Nearctic: Canada (Alberta, Labrado,r and Newfoundland), USA (Rocky Mts down to New Mexico). Palaearctic: from Europe eastwards to the Far East of Russia.

DNA Barcode.

BOLDBIN: BOLD:AAC1021 (BIN merge with D. quadrisetosa ). See Suppl. material 1: Table S1 for GenBank accession numbers.

Remarks.

We were recently informed that the holotype of Aspilia glacialis Rondani, previously considered lost ( Hennig 1962b: 677; Pont 1986: 73), had been located in the Museo di Storia Naturale, Sezione di Zoologia ‘’ La Specola’’, Università di Firenze ( MZUF). While we did not examine this material ourselves, the specimen has been unambiguously recognised by A.C. Pont as D. alpicola (pers. comm.) and we consider his expertise sufficient to recognise that the earlier name of D. glacialis must be given precedence over D. alpicola . Additional details about this new synonymy will be published in an upcoming work (A.C. Pont, pers. comm.).

In the Nearctic region, females of this Holarctic species can be distinguished from those of D. quadrisetosa only by the slightly darker wing base. However, this colour character appears variable in the Palaearctic region where Russian material shows a darker wing base (congruent with Nearctic females) while females from a series we examined from Austria as well as the holotype of D. glacialis (A.C. Pont pers. comm.) display a pale wing base similar to that of D. quadrisetosa , a species known only from the Nearctic region.

DNA barcodes for D. glacialis (all from Russian specimens) were very similar to those of D. quadrisetosa (specimens from Russia and Canada), forming a cluster with p-distances ranging from 0.0% to 1.72% for BOLD:AAC1021 (Fig. 25 ). Males of these two species can be easily distinguished based on distinctive leg chaetotaxy (see key to males) but since DNA barcodes do not discriminate between the two species, the identification of females can be problematic in the Nearctic region, as differences in wing base colour between the two taxa can sometimes be very subtle, especially for material kept in ethanol for long periods.

Figures

Figure 2. Male hind tibia, dorsal view A D. ponti B D. aterrima C D. groenlandica D D. setibasis E D. similis F D. vockerothi G D. quadrisetosa H D. glacialis I D. hucketti J D. woodorum. Scale bars: 0.5 mm.

Figure 4. Male head, lateral view A D. pribilofensis B D. neoborealis C D. vockerothi D D. spinitarsis E D. glacialis F D. santamonicae G D. amnicola H D. minor. Scale bars: 0.5 mm.

Figure 6. Male mid femur, anterior view (except G, H, L) A D. cantabrigensis B D. setibasis C D. vockerothi D D. profrontalis E D. glacialis F D. quadrisetosa G D. santamonicae, antero-dorsal view H D. amnicola, postero-dorsal view I D. similis J D. amnicola K D. hucketti L D. aldrichi, ventral view. Scale bars: 0.25 mm.

Figure 25. Neighbour-joining tree based on p-distance of all COI sequences (> 550 bp) for which specimens were examined. Each terminal includes the species name, BOLD process ID number, country of collection, and Barcode Index Number. Red text indicates the presence of more than one named species grouped under a single BIN (BIN merge).